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How do I test my lib?

  • I am creating a subdirs project which will have several libs. Some of these are open source and come with tests, so I want to include the tests in the project.

    The first was simple as the source contains a command-line executable dedicated to doing a quick test. I made that into one of my sub projects.

    The next creates several command-line executables one of which is used for testing, but the testing is done by a bit of bash type script:

    rm -f testout
    ./djpeg -dct int -ppm -outfile testout.ppm $(srcdir)/testorig.jpg
    ./djpeg -dct int -bmp -colors 256 -outfile testout.bmp $(srcdir)/testorig.jpg
    ./cjpeg -dct int -outfile testout.jpg $(srcdir)/testimg.ppm
    ./djpeg -dct int -ppm -outfile testoutp.ppm $(srcdir)/testprog.jpg
    ./cjpeg -dct int -progressive -opt -outfile testoutp.jpg $(srcdir)/testimg.ppm
    ./jpegtran -outfile testoutt.jpg $(srcdir)/testprog.jpg
    cmp $(srcdir)/testimg.ppm testout.ppm
    cmp $(srcdir)/testimg.bmp testout.bmp
    cmp $(srcdir)/testimg.jpg testout.jpg
    cmp $(srcdir)/testimg.ppm testoutp.ppm
    cmp $(srcdir)/testimgp.jpg testoutp.jpg
    cmp $(srcdir)/testorig.jpg testoutt.jpg

    Can I do something like that in Qt?
    And how do I declare the resource files (*.jpg) that I will need? They will need to be copied to wherever the executable get executed.....

  • Qt Champions 2017

    What is that you wanted in Qt ? Question is not very clear. Do you want execute one by one ?give more details.

  • @dheerendra OK thinking more clearly about this I can narrow down my requirement.... part of the problem is that I am new to this build system and so do not know the correct questions to ask.

    What I would like to do is:

    • build a command-line executable
    • run the executable on a particular file (input file)
    • compare the resulting file to a file representing the expected result (reference file), and report/throw an error if they differ.

    So I guess there are several gaps in my knowledge:

    • how do I know where my input file is - I can store it in git but the app is run in a different directory. Presumably where it is built, and that may vary. So somehow I need to make sure that my input and reference files wind up in the directory with the app.
    • How do I run a system command (in this case file compare) automatically after the app. Is this even a thing in Qt?
    • How do I flag up an error result

    I am sort of thinking of a target (subdir app) that runs and its output tells me that the lib built fine. Maybe I am expecting too much of this build system -gradle does this testing type thing, but then gradle does not give me the multiplatform support that Qt does.

  • Lifetime Qt Champion


    You are likely looking for the QtTest module.

    Your reference file(s) should be part of the sources. You can, for example, create a define that will contain the absolute path to your resource for the test for find it.

  • @SGaist Thankyou, that looks at first glance to be exactly what I need.

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